The present invention relates to a voice, data, and telephone network intended to operate over a cable. More specifically, a preferred embodiment of the invention comprises a fiber optic telephone and cable TV system with data capabilities.
Telephone systems have become an integral part of communications in the world today. However, most telephone systems use the same architecture which was used by telephone systems when they were originally conceived in the early 1900's.
Specifically, when telephone systems were first being put into normal use, these telephone systems consisted of nothing more than a plurality of wires each run to a house in the telephone system, and a switchboard operator who manually patched one wire into another. To make a long distance call, the switchboard operator would contact another switchboard operator, and the calls would be manually patched together. As time went on, and with the advent of mechanization, the switchboard operator was replaced with an automated switching system. However, this automated switching system performed the exact function of the operator--patching one telephone to another to complete the call. Because of this evolution of telephone systems, today's typical telephone system will have relatively dumb or unintelligent telephones, with most of the intelligence concentrated at the central office switching area. Thus, while various intelligent functions have been built into the central office system, the typical telephone is still a relatively unsophisticated piece of machinery. In addition, the typical telephone system has a dedicated pair of wires running from the central office to the telephone itself.
This leads to numerous problems. Most serious among these problems is the necessity to run a dedicated wire pair or more for each telephone in use. As the number of subscribers in an area increases, the number of lines also increases, and it may become necessary to run additional lines into the area. In addition, it becomes necessary to keep careful track of each of a plurality of lines, as each line in the bundle must go to a special location.
Many intelligent telephone systems are on the market today, known generally as PABXs, or private automatic branch exchanges. These PABXs will provide intelligence to the local telephone system, so that each telephone can perform a plurality of functions. However, these PABXs are in turn coupled to the existing telephone system, and thus have all the same drawbacks that were discussed above. Specifically, it is necessary to run a dedicated line for each telephone number. Also, all switching functions occur at the central office, and, even though the PABX has a lot of intelligence built therein, this intelligence can only be used to simulate the unsophisticated telephone that the central office expects.
A need clearly exists for a telephone system with distributed intelligence, and one especially useful with the advent of wide-band cable, such as optical fibers.
Accordingly, the present invention is such a system in which a controller is located at the central office, and a controller is located at each subscriber premise. The controller at each subscriber premise performs various preprocessing functions and sends messages to the controller at the central office. The controller at the central office, in turn, determines the operations which should occur between various structures, and commands the various controllers at premise locations to perform these functions. In a preferred embodiment of this invention, the telephone information for a plurality of subscriber premises is sent over a single optical fiber. This fiber is split off at various locations so that this fiber can go to a plurality of locations. Another aspect of this invention involves coupling cable TV (CATV) information onto this same fiber optical distribution network.
The prior art, for various reasons, has never performed this function. Many problems would exist as an impediment to one of ordinary skill in the art, and these problems have been overcome according to the present invention. These problems include structure necessary to provide a relatively inexpensive but highly functional system, including a structure and method which uses inexpensive lasers or LEDS, in order to perform the function usually performed by an expensive laser. Another problem which is overcome by the present invention is that of synchronization between the remote and local ends.